xref: /freebsd/sys/contrib/openzfs/module/os/linux/spl/spl-generic.c (revision 6be3386466ab79a84b48429ae66244f21526d3df)
1 /*
2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
3  *  Copyright (C) 2007 The Regents of the University of California.
4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
6  *  UCRL-CODE-235197
7  *
8  *  This file is part of the SPL, Solaris Porting Layer.
9  *
10  *  The SPL is free software; you can redistribute it and/or modify it
11  *  under the terms of the GNU General Public License as published by the
12  *  Free Software Foundation; either version 2 of the License, or (at your
13  *  option) any later version.
14  *
15  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
16  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
18  *  for more details.
19  *
20  *  You should have received a copy of the GNU General Public License along
21  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
22  *
23  *  Solaris Porting Layer (SPL) Generic Implementation.
24  */
25 
26 #include <sys/sysmacros.h>
27 #include <sys/systeminfo.h>
28 #include <sys/vmsystm.h>
29 #include <sys/kmem.h>
30 #include <sys/kmem_cache.h>
31 #include <sys/vmem.h>
32 #include <sys/mutex.h>
33 #include <sys/rwlock.h>
34 #include <sys/taskq.h>
35 #include <sys/tsd.h>
36 #include <sys/zmod.h>
37 #include <sys/debug.h>
38 #include <sys/proc.h>
39 #include <sys/kstat.h>
40 #include <sys/file.h>
41 #include <sys/sunddi.h>
42 #include <linux/ctype.h>
43 #include <sys/disp.h>
44 #include <sys/random.h>
45 #include <sys/strings.h>
46 #include <linux/kmod.h>
47 #include "zfs_gitrev.h"
48 #include <linux/mod_compat.h>
49 #include <sys/cred.h>
50 #include <sys/vnode.h>
51 
52 char spl_gitrev[64] = ZFS_META_GITREV;
53 
54 /* BEGIN CSTYLED */
55 unsigned long spl_hostid = 0;
56 EXPORT_SYMBOL(spl_hostid);
57 /* BEGIN CSTYLED */
58 module_param(spl_hostid, ulong, 0644);
59 MODULE_PARM_DESC(spl_hostid, "The system hostid.");
60 /* END CSTYLED */
61 
62 proc_t p0;
63 EXPORT_SYMBOL(p0);
64 
65 /*
66  * Xorshift Pseudo Random Number Generator based on work by Sebastiano Vigna
67  *
68  * "Further scramblings of Marsaglia's xorshift generators"
69  * http://vigna.di.unimi.it/ftp/papers/xorshiftplus.pdf
70  *
71  * random_get_pseudo_bytes() is an API function on Illumos whose sole purpose
72  * is to provide bytes containing random numbers. It is mapped to /dev/urandom
73  * on Illumos, which uses a "FIPS 186-2 algorithm". No user of the SPL's
74  * random_get_pseudo_bytes() needs bytes that are of cryptographic quality, so
75  * we can implement it using a fast PRNG that we seed using Linux' actual
76  * equivalent to random_get_pseudo_bytes(). We do this by providing each CPU
77  * with an independent seed so that all calls to random_get_pseudo_bytes() are
78  * free of atomic instructions.
79  *
80  * A consequence of using a fast PRNG is that using random_get_pseudo_bytes()
81  * to generate words larger than 128 bits will paradoxically be limited to
82  * `2^128 - 1` possibilities. This is because we have a sequence of `2^128 - 1`
83  * 128-bit words and selecting the first will implicitly select the second. If
84  * a caller finds this behavior undesirable, random_get_bytes() should be used
85  * instead.
86  *
87  * XXX: Linux interrupt handlers that trigger within the critical section
88  * formed by `s[1] = xp[1];` and `xp[0] = s[0];` and call this function will
89  * see the same numbers. Nothing in the code currently calls this in an
90  * interrupt handler, so this is considered to be okay. If that becomes a
91  * problem, we could create a set of per-cpu variables for interrupt handlers
92  * and use them when in_interrupt() from linux/preempt_mask.h evaluates to
93  * true.
94  */
95 void __percpu *spl_pseudo_entropy;
96 
97 /*
98  * spl_rand_next()/spl_rand_jump() are copied from the following CC-0 licensed
99  * file:
100  *
101  * http://xorshift.di.unimi.it/xorshift128plus.c
102  */
103 
104 static inline uint64_t
105 spl_rand_next(uint64_t *s)
106 {
107 	uint64_t s1 = s[0];
108 	const uint64_t s0 = s[1];
109 	s[0] = s0;
110 	s1 ^= s1 << 23; // a
111 	s[1] = s1 ^ s0 ^ (s1 >> 18) ^ (s0 >> 5); // b, c
112 	return (s[1] + s0);
113 }
114 
115 static inline void
116 spl_rand_jump(uint64_t *s)
117 {
118 	static const uint64_t JUMP[] =
119 	    { 0x8a5cd789635d2dff, 0x121fd2155c472f96 };
120 
121 	uint64_t s0 = 0;
122 	uint64_t s1 = 0;
123 	int i, b;
124 	for (i = 0; i < sizeof (JUMP) / sizeof (*JUMP); i++)
125 		for (b = 0; b < 64; b++) {
126 			if (JUMP[i] & 1ULL << b) {
127 				s0 ^= s[0];
128 				s1 ^= s[1];
129 			}
130 			(void) spl_rand_next(s);
131 		}
132 
133 	s[0] = s0;
134 	s[1] = s1;
135 }
136 
137 int
138 random_get_pseudo_bytes(uint8_t *ptr, size_t len)
139 {
140 	uint64_t *xp, s[2];
141 
142 	ASSERT(ptr);
143 
144 	xp = get_cpu_ptr(spl_pseudo_entropy);
145 
146 	s[0] = xp[0];
147 	s[1] = xp[1];
148 
149 	while (len) {
150 		union {
151 			uint64_t ui64;
152 			uint8_t byte[sizeof (uint64_t)];
153 		}entropy;
154 		int i = MIN(len, sizeof (uint64_t));
155 
156 		len -= i;
157 		entropy.ui64 = spl_rand_next(s);
158 
159 		while (i--)
160 			*ptr++ = entropy.byte[i];
161 	}
162 
163 	xp[0] = s[0];
164 	xp[1] = s[1];
165 
166 	put_cpu_ptr(spl_pseudo_entropy);
167 
168 	return (0);
169 }
170 
171 
172 EXPORT_SYMBOL(random_get_pseudo_bytes);
173 
174 #if BITS_PER_LONG == 32
175 
176 /*
177  * Support 64/64 => 64 division on a 32-bit platform.  While the kernel
178  * provides a div64_u64() function for this we do not use it because the
179  * implementation is flawed.  There are cases which return incorrect
180  * results as late as linux-2.6.35.  Until this is fixed upstream the
181  * spl must provide its own implementation.
182  *
183  * This implementation is a slightly modified version of the algorithm
184  * proposed by the book 'Hacker's Delight'.  The original source can be
185  * found here and is available for use without restriction.
186  *
187  * http://www.hackersdelight.org/HDcode/newCode/divDouble.c
188  */
189 
190 /*
191  * Calculate number of leading of zeros for a 64-bit value.
192  */
193 static int
194 nlz64(uint64_t x)
195 {
196 	register int n = 0;
197 
198 	if (x == 0)
199 		return (64);
200 
201 	if (x <= 0x00000000FFFFFFFFULL) { n = n + 32; x = x << 32; }
202 	if (x <= 0x0000FFFFFFFFFFFFULL) { n = n + 16; x = x << 16; }
203 	if (x <= 0x00FFFFFFFFFFFFFFULL) { n = n +  8; x = x <<  8; }
204 	if (x <= 0x0FFFFFFFFFFFFFFFULL) { n = n +  4; x = x <<  4; }
205 	if (x <= 0x3FFFFFFFFFFFFFFFULL) { n = n +  2; x = x <<  2; }
206 	if (x <= 0x7FFFFFFFFFFFFFFFULL) { n = n +  1; }
207 
208 	return (n);
209 }
210 
211 /*
212  * Newer kernels have a div_u64() function but we define our own
213  * to simplify portability between kernel versions.
214  */
215 static inline uint64_t
216 __div_u64(uint64_t u, uint32_t v)
217 {
218 	(void) do_div(u, v);
219 	return (u);
220 }
221 
222 /*
223  * Turn off missing prototypes warning for these functions. They are
224  * replacements for libgcc-provided functions and will never be called
225  * directly.
226  */
227 #pragma GCC diagnostic push
228 #pragma GCC diagnostic ignored "-Wmissing-prototypes"
229 
230 /*
231  * Implementation of 64-bit unsigned division for 32-bit machines.
232  *
233  * First the procedure takes care of the case in which the divisor is a
234  * 32-bit quantity. There are two subcases: (1) If the left half of the
235  * dividend is less than the divisor, one execution of do_div() is all that
236  * is required (overflow is not possible). (2) Otherwise it does two
237  * divisions, using the grade school method.
238  */
239 uint64_t
240 __udivdi3(uint64_t u, uint64_t v)
241 {
242 	uint64_t u0, u1, v1, q0, q1, k;
243 	int n;
244 
245 	if (v >> 32 == 0) {			// If v < 2**32:
246 		if (u >> 32 < v) {		// If u/v cannot overflow,
247 			return (__div_u64(u, v)); // just do one division.
248 		} else {			// If u/v would overflow:
249 			u1 = u >> 32;		// Break u into two halves.
250 			u0 = u & 0xFFFFFFFF;
251 			q1 = __div_u64(u1, v);	// First quotient digit.
252 			k  = u1 - q1 * v;	// First remainder, < v.
253 			u0 += (k << 32);
254 			q0 = __div_u64(u0, v);	// Seconds quotient digit.
255 			return ((q1 << 32) + q0);
256 		}
257 	} else {				// If v >= 2**32:
258 		n = nlz64(v);			// 0 <= n <= 31.
259 		v1 = (v << n) >> 32;		// Normalize divisor, MSB is 1.
260 		u1 = u >> 1;			// To ensure no overflow.
261 		q1 = __div_u64(u1, v1);		// Get quotient from
262 		q0 = (q1 << n) >> 31;		// Undo normalization and
263 						// division of u by 2.
264 		if (q0 != 0)			// Make q0 correct or
265 			q0 = q0 - 1;		// too small by 1.
266 		if ((u - q0 * v) >= v)
267 			q0 = q0 + 1;		// Now q0 is correct.
268 
269 		return (q0);
270 	}
271 }
272 EXPORT_SYMBOL(__udivdi3);
273 
274 /* BEGIN CSTYLED */
275 #ifndef abs64
276 #define	abs64(x)	({ uint64_t t = (x) >> 63; ((x) ^ t) - t; })
277 #endif
278 /* END CSTYLED */
279 
280 /*
281  * Implementation of 64-bit signed division for 32-bit machines.
282  */
283 int64_t
284 __divdi3(int64_t u, int64_t v)
285 {
286 	int64_t q, t;
287 	q = __udivdi3(abs64(u), abs64(v));
288 	t = (u ^ v) >> 63;	// If u, v have different
289 	return ((q ^ t) - t);	// signs, negate q.
290 }
291 EXPORT_SYMBOL(__divdi3);
292 
293 /*
294  * Implementation of 64-bit unsigned modulo for 32-bit machines.
295  */
296 uint64_t
297 __umoddi3(uint64_t dividend, uint64_t divisor)
298 {
299 	return (dividend - (divisor * __udivdi3(dividend, divisor)));
300 }
301 EXPORT_SYMBOL(__umoddi3);
302 
303 /* 64-bit signed modulo for 32-bit machines. */
304 int64_t
305 __moddi3(int64_t n, int64_t d)
306 {
307 	int64_t q;
308 	boolean_t nn = B_FALSE;
309 
310 	if (n < 0) {
311 		nn = B_TRUE;
312 		n = -n;
313 	}
314 	if (d < 0)
315 		d = -d;
316 
317 	q = __umoddi3(n, d);
318 
319 	return (nn ? -q : q);
320 }
321 EXPORT_SYMBOL(__moddi3);
322 
323 /*
324  * Implementation of 64-bit unsigned division/modulo for 32-bit machines.
325  */
326 uint64_t
327 __udivmoddi4(uint64_t n, uint64_t d, uint64_t *r)
328 {
329 	uint64_t q = __udivdi3(n, d);
330 	if (r)
331 		*r = n - d * q;
332 	return (q);
333 }
334 EXPORT_SYMBOL(__udivmoddi4);
335 
336 /*
337  * Implementation of 64-bit signed division/modulo for 32-bit machines.
338  */
339 int64_t
340 __divmoddi4(int64_t n, int64_t d, int64_t *r)
341 {
342 	int64_t q, rr;
343 	boolean_t nn = B_FALSE;
344 	boolean_t nd = B_FALSE;
345 	if (n < 0) {
346 		nn = B_TRUE;
347 		n = -n;
348 	}
349 	if (d < 0) {
350 		nd = B_TRUE;
351 		d = -d;
352 	}
353 
354 	q = __udivmoddi4(n, d, (uint64_t *)&rr);
355 
356 	if (nn != nd)
357 		q = -q;
358 	if (nn)
359 		rr = -rr;
360 	if (r)
361 		*r = rr;
362 	return (q);
363 }
364 EXPORT_SYMBOL(__divmoddi4);
365 
366 #if defined(__arm) || defined(__arm__)
367 /*
368  * Implementation of 64-bit (un)signed division for 32-bit arm machines.
369  *
370  * Run-time ABI for the ARM Architecture (page 20).  A pair of (unsigned)
371  * long longs is returned in {{r0, r1}, {r2,r3}}, the quotient in {r0, r1},
372  * and the remainder in {r2, r3}.  The return type is specifically left
373  * set to 'void' to ensure the compiler does not overwrite these registers
374  * during the return.  All results are in registers as per ABI
375  */
376 void
377 __aeabi_uldivmod(uint64_t u, uint64_t v)
378 {
379 	uint64_t res;
380 	uint64_t mod;
381 
382 	res = __udivdi3(u, v);
383 	mod = __umoddi3(u, v);
384 	{
385 		register uint32_t r0 asm("r0") = (res & 0xFFFFFFFF);
386 		register uint32_t r1 asm("r1") = (res >> 32);
387 		register uint32_t r2 asm("r2") = (mod & 0xFFFFFFFF);
388 		register uint32_t r3 asm("r3") = (mod >> 32);
389 
390 		/* BEGIN CSTYLED */
391 		asm volatile(""
392 		    : "+r"(r0), "+r"(r1), "+r"(r2),"+r"(r3)  /* output */
393 		    : "r"(r0), "r"(r1), "r"(r2), "r"(r3));   /* input */
394 		/* END CSTYLED */
395 
396 		return; /* r0; */
397 	}
398 }
399 EXPORT_SYMBOL(__aeabi_uldivmod);
400 
401 void
402 __aeabi_ldivmod(int64_t u, int64_t v)
403 {
404 	int64_t res;
405 	uint64_t mod;
406 
407 	res =  __divdi3(u, v);
408 	mod = __umoddi3(u, v);
409 	{
410 		register uint32_t r0 asm("r0") = (res & 0xFFFFFFFF);
411 		register uint32_t r1 asm("r1") = (res >> 32);
412 		register uint32_t r2 asm("r2") = (mod & 0xFFFFFFFF);
413 		register uint32_t r3 asm("r3") = (mod >> 32);
414 
415 		/* BEGIN CSTYLED */
416 		asm volatile(""
417 		    : "+r"(r0), "+r"(r1), "+r"(r2),"+r"(r3)  /* output */
418 		    : "r"(r0), "r"(r1), "r"(r2), "r"(r3));   /* input */
419 		/* END CSTYLED */
420 
421 		return; /* r0; */
422 	}
423 }
424 EXPORT_SYMBOL(__aeabi_ldivmod);
425 #endif /* __arm || __arm__ */
426 
427 #pragma GCC diagnostic pop
428 
429 #endif /* BITS_PER_LONG */
430 
431 /*
432  * NOTE: The strtoxx behavior is solely based on my reading of the Solaris
433  * ddi_strtol(9F) man page.  I have not verified the behavior of these
434  * functions against their Solaris counterparts.  It is possible that I
435  * may have misinterpreted the man page or the man page is incorrect.
436  */
437 int ddi_strtoul(const char *, char **, int, unsigned long *);
438 int ddi_strtol(const char *, char **, int, long *);
439 int ddi_strtoull(const char *, char **, int, unsigned long long *);
440 int ddi_strtoll(const char *, char **, int, long long *);
441 
442 #define	define_ddi_strtoux(type, valtype)				\
443 int ddi_strtou##type(const char *str, char **endptr,			\
444     int base, valtype *result)						\
445 {									\
446 	valtype last_value, value = 0;					\
447 	char *ptr = (char *)str;					\
448 	int flag = 1, digit;						\
449 									\
450 	if (strlen(ptr) == 0)						\
451 		return (EINVAL);					\
452 									\
453 	/* Auto-detect base based on prefix */				\
454 	if (!base) {							\
455 		if (str[0] == '0') {					\
456 			if (tolower(str[1]) == 'x' && isxdigit(str[2])) { \
457 				base = 16; /* hex */			\
458 				ptr += 2;				\
459 			} else if (str[1] >= '0' && str[1] < 8) {	\
460 				base = 8; /* octal */			\
461 				ptr += 1;				\
462 			} else {					\
463 				return (EINVAL);			\
464 			}						\
465 		} else {						\
466 			base = 10; /* decimal */			\
467 		}							\
468 	}								\
469 									\
470 	while (1) {							\
471 		if (isdigit(*ptr))					\
472 			digit = *ptr - '0';				\
473 		else if (isalpha(*ptr))					\
474 			digit = tolower(*ptr) - 'a' + 10;		\
475 		else							\
476 			break;						\
477 									\
478 		if (digit >= base)					\
479 			break;						\
480 									\
481 		last_value = value;					\
482 		value = value * base + digit;				\
483 		if (last_value > value) /* Overflow */			\
484 			return (ERANGE);				\
485 									\
486 		flag = 1;						\
487 		ptr++;							\
488 	}								\
489 									\
490 	if (flag)							\
491 		*result = value;					\
492 									\
493 	if (endptr)							\
494 		*endptr = (char *)(flag ? ptr : str);			\
495 									\
496 	return (0);							\
497 }									\
498 
499 #define	define_ddi_strtox(type, valtype)				\
500 int ddi_strto##type(const char *str, char **endptr,			\
501     int base, valtype *result)						\
502 {									\
503 	int rc;								\
504 									\
505 	if (*str == '-') {						\
506 		rc = ddi_strtou##type(str + 1, endptr, base, result);	\
507 		if (!rc) {						\
508 			if (*endptr == str + 1)				\
509 				*endptr = (char *)str;			\
510 			else						\
511 				*result = -*result;			\
512 		}							\
513 	} else {							\
514 		rc = ddi_strtou##type(str, endptr, base, result);	\
515 	}								\
516 									\
517 	return (rc);							\
518 }
519 
520 define_ddi_strtoux(l, unsigned long)
521 define_ddi_strtox(l, long)
522 define_ddi_strtoux(ll, unsigned long long)
523 define_ddi_strtox(ll, long long)
524 
525 EXPORT_SYMBOL(ddi_strtoul);
526 EXPORT_SYMBOL(ddi_strtol);
527 EXPORT_SYMBOL(ddi_strtoll);
528 EXPORT_SYMBOL(ddi_strtoull);
529 
530 int
531 ddi_copyin(const void *from, void *to, size_t len, int flags)
532 {
533 	/* Fake ioctl() issued by kernel, 'from' is a kernel address */
534 	if (flags & FKIOCTL) {
535 		memcpy(to, from, len);
536 		return (0);
537 	}
538 
539 	return (copyin(from, to, len));
540 }
541 EXPORT_SYMBOL(ddi_copyin);
542 
543 int
544 ddi_copyout(const void *from, void *to, size_t len, int flags)
545 {
546 	/* Fake ioctl() issued by kernel, 'from' is a kernel address */
547 	if (flags & FKIOCTL) {
548 		memcpy(to, from, len);
549 		return (0);
550 	}
551 
552 	return (copyout(from, to, len));
553 }
554 EXPORT_SYMBOL(ddi_copyout);
555 
556 static ssize_t
557 spl_kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
558 {
559 #if defined(HAVE_KERNEL_READ_PPOS)
560 	return (kernel_read(file, buf, count, pos));
561 #else
562 	mm_segment_t saved_fs;
563 	ssize_t ret;
564 
565 	saved_fs = get_fs();
566 	set_fs(KERNEL_DS);
567 
568 	ret = vfs_read(file, (void __user *)buf, count, pos);
569 
570 	set_fs(saved_fs);
571 
572 	return (ret);
573 #endif
574 }
575 
576 static int
577 spl_getattr(struct file *filp, struct kstat *stat)
578 {
579 	int rc;
580 
581 	ASSERT(filp);
582 	ASSERT(stat);
583 
584 #if defined(HAVE_4ARGS_VFS_GETATTR)
585 	rc = vfs_getattr(&filp->f_path, stat, STATX_BASIC_STATS,
586 	    AT_STATX_SYNC_AS_STAT);
587 #elif defined(HAVE_2ARGS_VFS_GETATTR)
588 	rc = vfs_getattr(&filp->f_path, stat);
589 #else
590 	rc = vfs_getattr(filp->f_path.mnt, filp->f_dentry, stat);
591 #endif
592 	if (rc)
593 		return (-rc);
594 
595 	return (0);
596 }
597 
598 /*
599  * Read the unique system identifier from the /etc/hostid file.
600  *
601  * The behavior of /usr/bin/hostid on Linux systems with the
602  * regular eglibc and coreutils is:
603  *
604  *   1. Generate the value if the /etc/hostid file does not exist
605  *      or if the /etc/hostid file is less than four bytes in size.
606  *
607  *   2. If the /etc/hostid file is at least 4 bytes, then return
608  *      the first four bytes [0..3] in native endian order.
609  *
610  *   3. Always ignore bytes [4..] if they exist in the file.
611  *
612  * Only the first four bytes are significant, even on systems that
613  * have a 64-bit word size.
614  *
615  * See:
616  *
617  *   eglibc: sysdeps/unix/sysv/linux/gethostid.c
618  *   coreutils: src/hostid.c
619  *
620  * Notes:
621  *
622  * The /etc/hostid file on Solaris is a text file that often reads:
623  *
624  *   # DO NOT EDIT
625  *   "0123456789"
626  *
627  * Directly copying this file to Linux results in a constant
628  * hostid of 4f442023 because the default comment constitutes
629  * the first four bytes of the file.
630  *
631  */
632 
633 char *spl_hostid_path = HW_HOSTID_PATH;
634 module_param(spl_hostid_path, charp, 0444);
635 MODULE_PARM_DESC(spl_hostid_path, "The system hostid file (/etc/hostid)");
636 
637 static int
638 hostid_read(uint32_t *hostid)
639 {
640 	uint64_t size;
641 	uint32_t value = 0;
642 	int error;
643 	loff_t off;
644 	struct file *filp;
645 	struct kstat stat;
646 
647 	filp = filp_open(spl_hostid_path, 0, 0);
648 
649 	if (IS_ERR(filp))
650 		return (ENOENT);
651 
652 	error = spl_getattr(filp, &stat);
653 	if (error) {
654 		filp_close(filp, 0);
655 		return (error);
656 	}
657 	size = stat.size;
658 	if (size < sizeof (HW_HOSTID_MASK)) {
659 		filp_close(filp, 0);
660 		return (EINVAL);
661 	}
662 
663 	off = 0;
664 	/*
665 	 * Read directly into the variable like eglibc does.
666 	 * Short reads are okay; native behavior is preserved.
667 	 */
668 	error = spl_kernel_read(filp, &value, sizeof (value), &off);
669 	if (error < 0) {
670 		filp_close(filp, 0);
671 		return (EIO);
672 	}
673 
674 	/* Mask down to 32 bits like coreutils does. */
675 	*hostid = (value & HW_HOSTID_MASK);
676 	filp_close(filp, 0);
677 
678 	return (0);
679 }
680 
681 /*
682  * Return the system hostid.  Preferentially use the spl_hostid module option
683  * when set, otherwise use the value in the /etc/hostid file.
684  */
685 uint32_t
686 zone_get_hostid(void *zone)
687 {
688 	uint32_t hostid;
689 
690 	ASSERT3P(zone, ==, NULL);
691 
692 	if (spl_hostid != 0)
693 		return ((uint32_t)(spl_hostid & HW_HOSTID_MASK));
694 
695 	if (hostid_read(&hostid) == 0)
696 		return (hostid);
697 
698 	return (0);
699 }
700 EXPORT_SYMBOL(zone_get_hostid);
701 
702 static int
703 spl_kvmem_init(void)
704 {
705 	int rc = 0;
706 
707 	rc = spl_kmem_init();
708 	if (rc)
709 		return (rc);
710 
711 	rc = spl_vmem_init();
712 	if (rc) {
713 		spl_kmem_fini();
714 		return (rc);
715 	}
716 
717 	return (rc);
718 }
719 
720 /*
721  * We initialize the random number generator with 128 bits of entropy from the
722  * system random number generator. In the improbable case that we have a zero
723  * seed, we fallback to the system jiffies, unless it is also zero, in which
724  * situation we use a preprogrammed seed. We step forward by 2^64 iterations to
725  * initialize each of the per-cpu seeds so that the sequences generated on each
726  * CPU are guaranteed to never overlap in practice.
727  */
728 static void __init
729 spl_random_init(void)
730 {
731 	uint64_t s[2];
732 	int i = 0;
733 
734 	spl_pseudo_entropy = __alloc_percpu(2 * sizeof (uint64_t),
735 	    sizeof (uint64_t));
736 
737 	get_random_bytes(s, sizeof (s));
738 
739 	if (s[0] == 0 && s[1] == 0) {
740 		if (jiffies != 0) {
741 			s[0] = jiffies;
742 			s[1] = ~0 - jiffies;
743 		} else {
744 			(void) memcpy(s, "improbable seed", sizeof (s));
745 		}
746 		printk("SPL: get_random_bytes() returned 0 "
747 		    "when generating random seed. Setting initial seed to "
748 		    "0x%016llx%016llx.\n", cpu_to_be64(s[0]),
749 		    cpu_to_be64(s[1]));
750 	}
751 
752 	for_each_possible_cpu(i) {
753 		uint64_t *wordp = per_cpu_ptr(spl_pseudo_entropy, i);
754 
755 		spl_rand_jump(s);
756 
757 		wordp[0] = s[0];
758 		wordp[1] = s[1];
759 	}
760 }
761 
762 static void
763 spl_random_fini(void)
764 {
765 	free_percpu(spl_pseudo_entropy);
766 }
767 
768 static void
769 spl_kvmem_fini(void)
770 {
771 	spl_vmem_fini();
772 	spl_kmem_fini();
773 }
774 
775 static int __init
776 spl_init(void)
777 {
778 	int rc = 0;
779 
780 	bzero(&p0, sizeof (proc_t));
781 	spl_random_init();
782 
783 	if ((rc = spl_kvmem_init()))
784 		goto out1;
785 
786 	if ((rc = spl_tsd_init()))
787 		goto out2;
788 
789 	if ((rc = spl_taskq_init()))
790 		goto out3;
791 
792 	if ((rc = spl_kmem_cache_init()))
793 		goto out4;
794 
795 	if ((rc = spl_proc_init()))
796 		goto out5;
797 
798 	if ((rc = spl_kstat_init()))
799 		goto out6;
800 
801 	if ((rc = spl_zlib_init()))
802 		goto out7;
803 
804 	return (rc);
805 
806 out7:
807 	spl_kstat_fini();
808 out6:
809 	spl_proc_fini();
810 out5:
811 	spl_kmem_cache_fini();
812 out4:
813 	spl_taskq_fini();
814 out3:
815 	spl_tsd_fini();
816 out2:
817 	spl_kvmem_fini();
818 out1:
819 	return (rc);
820 }
821 
822 static void __exit
823 spl_fini(void)
824 {
825 	spl_zlib_fini();
826 	spl_kstat_fini();
827 	spl_proc_fini();
828 	spl_kmem_cache_fini();
829 	spl_taskq_fini();
830 	spl_tsd_fini();
831 	spl_kvmem_fini();
832 	spl_random_fini();
833 }
834 
835 module_init(spl_init);
836 module_exit(spl_fini);
837 
838 ZFS_MODULE_DESCRIPTION("Solaris Porting Layer");
839 ZFS_MODULE_AUTHOR(ZFS_META_AUTHOR);
840 ZFS_MODULE_LICENSE("GPL");
841 ZFS_MODULE_VERSION(ZFS_META_VERSION "-" ZFS_META_RELEASE);
842